When it comes to the health consequences associated with ultra-processed food (UPF) consumption, a new study suggests that there may be more at play than a food’s nutritional content and ingredients—the processing itself may have an influence.

The study was conducted by researchers at the Food is Medicine Institute at Tufts University’s Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy, and was published in the American Journal of Public Health as part of a landmark collection of peer-reviewed literature on UPFs policy, marketing practices, and public health impact.

Investigating Americans’ Diets

For the observational study, the researchers analyzed data from ten consecutive cycles of the U.S. National Health and Nutrition Examination Survey (NHANES) from 1999–2018, linked to the National Death Index through 2018. Study participants had completed one or two 24-hour dietary recalls.

Using a standard classification system, the team grouped foods based on how they were made—from minimally processed, food-based ingredients like fruits and vegetables to ultra-processed products made with industrial ingredients and additives that are not typically used in cooking. The researchers also rated the nutritional quality of foods using a system that scores foods based on their overall healthfulness.

Each participant received an overall diet-quality score based on the foods they reported eating. The team then examined how UPF consumption was linked to health indicators such as weight, blood sugar, and cholesterol, as well as the long-term risk of death.  

People Eating More UPFs Have Worse Health Outcomes, Regardless of Nutrition

Overall, the researchers found that people who ate more UPFs had worse health outcomes, even after accounting for the overall nutritional quality of the foods.

Specifically, for every 10 percent increase in a person’s caloric intake from UPFs, the researchers found worse health markers. People who ate more UPFs tended to have higher body weight, worse blood sugar control, higher blood pressure, and less favorable cholesterol levels. They were also more likely to have conditions such as diabetes, metabolic syndrome, and cancer, and also had a slightly higher risk of dying during the study period.

These links remained even after researchers accounted for reported foods’ nutrient quality and the amounts of saturated fat, added sugar, or sodium present in the UPFs people were eating. The patterns were largely the same across different population subgroups.

Supporting Systemic Change

As UPFs comprise more than 50 and 60 percent of U.S. adults’ and children’s diets, respectively, understanding these foods’ impact on public health is a critical priority, the researchers stress. They hope that their findings will be used to inform policy efforts, such as state laws (e.g., additives bans, school meal regulations, and warning labels) and a potential federal statutory UPFs definition.  

The study was led by Dariush Mozaffarian, M.D., Dr.P.H., cardiologist and Director of the Food is Medicine Institute. Co-authors included Lu Wang, Ph.D., M.P.H.; Bingbing Fan, Ph.D.; and Peilin Shi from the Friedman School of Nutrition Science and Policy.